video: fbdev: atyfb: Remove assigned but never used variable statements

There are a couple of statements where local variables are being assigned
values that are never read because the function returns immediately after
the assignment. Clean up the code by removing them.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Helge Deller <deller@gmx.de>